Exploring link between marriage and heart disease

Does the stress of marriage contribute to heart disease, which accounts for one of every four deaths in the United States?

A federally funded study aims to find out. Michigan State University’s Hui Liu will lead one of the first national interdisciplinary efforts to investigate how biology and social factors interact within marriage to affect cardiovascular health.

Liu is a medical sociologist whose previous research on the tie between relationships and health has been featured in the New York Times, Time, NBC News and other media outlets. The latest study is funded by a $619,645 grant from the National Institute on Aging, which is part of the National Institutes of Health.

“The importance of this study is highlighted by the continued high prevalence of cardiovascular disease in the United States,” Liu said. “We plan to provide nationally representative evidence on how marriage affects cardiovascular health and elucidate the multiple mechanisms in this relationship. The findings will have important implications for health policy and practice.”

Because most heart disease is preventable, identifying risk factors is crucial to design effective prevention strategies and programs. Many social, psychological, behavioral and biological factors work together to contribute to the risk of heart disease over people’s lifetime. The study will focus on people aged 50 and older based on two nationwide datasets from the National Social Life, Health and Aging Project and the Health and Retirement Study.

Scientists have long said marriage is the most important social relationship affecting health during adulthood. Both the stress and support within marriage shape life context, which in turn may affect health, Liu said. For example, a happy marriage may provide social support, which may buffer the negative consequences of stressful life events and in turn enhance physical health.

In contrast, a distressed marriage exposes an individual to stressful interactions that may lead to depression. Depression, in turn, affects health either indirectly, by promoting unhealthy behaviors such as smoking and drinking, or directly, by stimulating the production of stress hormones (e.g., catecholamine, cortisol), which in turn results in increased blood pressure and heart rate, accelerated breathing and constriction of blood vessels. This “fight or flight” process may foster wear and tear on the regulatory mechanisms of the human body and lead to chronic conditions such as heart disease and hypertension.

Liu said the study also will explore potential age and gender differences in the marital links with cardiovascular risk.

Her co-researchers include MSU researchers Donna Wang, a physician and professor of medicine; Clifford Broman, professor of sociology; Joseph Lonstein, associate professor of psychology; and Wenjiang Fu, associate professor of biostatistics in the Department of Epidemiology. The team also includes Linda Waite, sociologist at the University of Chicago, and Thomas McDade, anthropologist at Northwestern University.